1.3 No Sound
1) No audio signals at AV input circuit
• Check audio signals at pins14 and 15 of IC5011 on the AV Board. Check IC5011
and peripheral circuits.
2) Incorrect operation of VIDEO/COMPUTER mode switching
• Check AV/PC switching signal at pins 10 and 11 of IC5011. Check IC5011, IC801
and switching signal.
AV: Low, PC: High
3) No audio output signal at speaker
• Check audio signal at pins 1 and 3 of K8F on the Main Board.
Check MUTE signal at pin 1 of IC001.
Mute On: Low
• Check MUTE signal at pin 7 of IC1831, pins 7 and 13 of IC1881, and peripheral
circuit.
Mute On: High
• Check sound volume signal at pin 4 of IC001, and pin 14 of IC1831.
Check IC IC001, IC1831 and peripheral circuit.
Volume Min.: Low
4) No power supply at audio circuit
• Check 6V (6V AUDIO) power supply line.
Part 4: Troubleshooting
4-7
Fig. 4-3
IC2161
D/A
AV/PC
7
8
IC1831
D/A
AUDIO MUTE
IC1881
BUFFER
13
7
MUTE
IC5011
AUDIO-SW
1
13
2
12
10
11
15
14
PC_L/R
AV_L/R
IC001
AUDIO
CONTROL
2
1
4
6
8
Q5072
Q1816
Q1817
Q1818
Q1819
Q011
AV/PC
Q5031
Q5041
Q5051
Q5061
Q5081
Q5082
MUTE
VOLUME
SPEAKER
7
2
3
2
3
14
7
SCL2_5
SDA2_5
SCL1_5
SDA1_5
IC801
SUB
CPU
80,81
79,78
COMPUTER
AUDIO IN
VIDEO
AUDIO IN
MONITOR
AUDIO OUT
29
30
27
28
21
|
24
31
32
1,3
K3U
K10U
K8F
AV BOARD
MAIN BOARD
PC: H
AV: L
MUTE On: H
MUTE On: H
Summary of Contents for LV-7355J
Page 9: ...Part 1 General Information ...
Page 22: ...Part 2 Repair Information ...
Page 43: ...Part 3 Adjustment ...
Page 65: ...Part 4 Troubleshooting ...
Page 82: ...Part 4 Troubleshooting 4 17 BA7078AF Selector IC6241 CXA2101AQ RGB Matrix IC4101 ...
Page 85: ...Part 4 Troubleshooting 4 20 ML60851 USB I F IC9801 M62393 D A IC2571 ...
Page 86: ...Part 4 Troubleshooting 4 21 TB1274AF Video Decoder IC1101 TA1318N AFC Detector IC6171 ...
Page 88: ...Part 5 Parts Catalog ...
Page 89: ......
Page 107: ...Part 6 Electrical Diagrams ...
Page 117: ......